Work around crazy Chrome bug

When the ListToolGroup in the toolbar (the "More" section) is scrolled
down such that the top tool is partly obscured, and you hover over the
bottom half of the "More" button, the top tool displays a hover effect
and using the scroll wheel will scroll the list rather than the page.

This is because the list has a box-shadow that's 1em tall, and the
height of the "More" button is 2em. And in Chrome, pointer events
"work" even in the box-shadow area. Roan reported the Chrome bug at
https://code.google.com/p/chromium/issues/detail?id=314291

This change works around the bug by making the tools in the list
inline-block instead of block; for some reason the bug only affects
block elements.

Change-Id: I4ea3f41c91d0ff5d5cc150fe8acc3427f0ab5f3a
Merge "Work around crazy Chrome bug"